Congestive heart failure is a progressive and debilitating illness. The disease is characterized by a progressive enlargement of the heart. As the heart enlarges, it is required to perform an increasing amount of work in order to pump blood with each heartbeat. In time, the heart becomes so enlarged that it cannot adequately supply blood. An afflicted patient is fatigued, unable to perform even simple exerting tasks, and experiences pain and discomfort.
Patients suffering from congestive heart failure are commonly grouped into four classes (i.e., Classes I, II, III and IV). In the early stages (e.g., Classes I and II), drug therapy is the most commonly prescribed treatment. Drug therapy treats the symptoms of the disease and may slow the progression of the disease. Unfortunately, there is presently no cure for congestive heart failure. Even with drug therapy, the disease will progress.
One treatment for late-stage congestive heart failure is heart transplant. However, even if the patient qualifies for transplant and a heart is available for transplant, it is noted that heart transplant procedures are very risky, invasive, expensive and only shortly extend a patient's life. For example, prior to transplant, a Class IV patient may have a life expectancy of 6 months to one-year. Heart transplant may improve the expectancy to about five years. Similar risks and difficulties exist for mechanical heart transplants as well.
Another technique for the treatment for late stage congestive heart failure is a cardiomyoplasty procedure. In this procedure, the latissimus dorsi muscle (taken from the patient's shoulder) is wrapped around the heart and electrically paced synchronously with ventricular systole. Pacing of the muscle results in muscle contraction to assist the contraction of the heart during systole. However, even though cardiomyoplasty has demonstrated symptomatic improvement, studies suggest the procedure only minimally improves cardiac performance. Moreover, the procedure is highly invasive, expensive and complex, requiring harvesting a patient's muscle and an open chest approach (i.e., sternotomy) to access the heart.
Recently, a surgical procedure referred to as the Batista procedure has been developed. The procedure includes dissecting and removing portions of the heart in order to reduce heart volume. Others have used external constraints such as jackets, girdles, fabric slings or clamps to constrain and remodel the heart and reduce heart volume. See, e.g., U.S. Pat. No. 6,293,906 (citing numerous references including U.S. Pat. Nos. 5,702,343 and 5,800,528) and U.S. Pat. No. 6,095,968. In accordance with an example from the above '906 patent, a cardiac constraint device can be placed on an enlarged heart and fitted snug during diastole; for example, a knit jacket device can be loosely slipped on the heart, the material of the jacket can be gathered to adjust the device to a desired tension, and the gathered material can be sutured or otherwise fixed to maintain the tensioning.